new 26R1 error: A PXGraphExtension instance has been passed as a query parameter to the Select method

After upgrading to 26R1, I’m now getting this new Exception (didn’t happen in 24R1):

"A PXGraphExtension instance has been passed as a query parameter to the Select method."

This happens on a Select using the POLine object:

 public class POMaintExtension : PXGraphExtension<POOrderEntry>
    {

        public SelectFrom<POLine>
              .Where<POLine.orderNbr.IsEqual<
             POOrder.orderNbr.FromCurrent>>
            .View POLineView;

        private void DeviceHubPrint()
        {
            foreach (object objPOL in POLineView.SelectMain(this)) //throw Exception

...

Question: did something change with POLine causing this new behavior?